OsELP3/ELP4, rice Elongator factor complex subunits, epigenetically regulates rice blast resistance.

Abstract

Rice blast, caused by Magnaporthe oryzae (M.oryzae), is one of the three most devastating rice diseases, significantly reducing both yield and grain quality. The Elongator complex, first characterized in Arabidopsis thaliana, regulates growth, development, and innate immunity by tightly associating with hyperphosphorylated RNA polymerase II. However, its immunological role in rice remains unexplored. Here, we demonstrate that Elongator plays an essential role in rice blast resistance. The OsELP3 subunit mutant exhibited susceptibility to M.oryzae, while its overexpression increased resistance. OsELP3 interacts with its homologous subunit OsELP4 in the nucleus, and that OsELP4 also positively regulates rice blast resistance. RNA-seq and histone acetylation analyses demonstrated that OsELP3/ELP4 enhances transcriptional activation of key rice blast resistance genes by modulating histone acetylation levels in both the jasmonic acid (JA) signaling pathway (OsAOS1, OsLOX6, OsPROPEP3) and lignin biosynthesis pathway (OsMYB30, OsMYB55, OsMYB110), thereby strengthening plant defense mechanisms against M. oryzae. These findings reveal that OsELP3/ELP4 regulates histone acetylation-mediated defense responses against M.oryzae, providing both theoretical foundations and genetic resources for developing blast-resistant rice cultivars.